This multidisciplinary project examines the transmission dynamics of multiple parasite species and their interactive effect on human populations in developing areas of coastal Kenya. In this ecological setting, transmission of Schistosoma haematobium, Plasmodium spp., filarial nematodes, and geohelminths is common, resulting in high levels of human urinary schistosomiasis, malaria, lymphatic filariasis, and hookworm infection. These infections, because of their combined long-term effects, appear to play a significant but, as yet, incompletely defined synergistic role in the causation of chronic clinical and subclinical human disease and poverty. In this context, transmission patterns and risk factors for these diverse parasitic infections often appear to be linked and to overlap extensively. However, to date, most studies have not approached the complexity of multi-parasite ecology because of limitations on data availability and accuracy and because of variable heterogeneities of infection risk that are found across physical and social space, and over time. The project's underlying hypothesis is that environmental factors are the key determinants of transmission potential for these parasites, and that these interact with demographic and socio-economic factors in determining the observed spatial/demographic patterns of parasitic disease. Recent research findings on parasite eco-epidemiology indicate that these effects all need to be reconsidered on multiple levels-individual, household, village, and district-wide-separately for each parasite, and for the combined suite of infections. Transmission processes and disease patterns vary across these multiple levels, and will also vary spatially and temporally within each level. The combined impact of these endemic infections has not been well studied, and may prove to have additive or more complex non-linear interactive effects. Consequently, optimal control strategies may prove to require local reduction of both transmission (preventing infection) and disease manifestations through the integrated targeting of one, some, or all of these parasitic infections in concert. Specific Aims of this project are to detect spatial and demographic patterns of transmission and infection for schistosomiasis, malaria, filariasis, and hookworms in coastal Kenya through integration of parasitological data with landscape, land use, and socioeconomic risk factors;to develop network- and individual-based models to identify the critical features of transmission and predict the potential impact of integrated control programs on distribution of malaria, filaria, schistosomes, and hookworm, and their related community disease impact;and strengthen training in infectious disease ecology for health problems in Africa.